-LRB- CNN -RRB- -- A dispatcher who took a 911 call regarding a domestic argument at a Pittsburgh , Pennsylvania-area home knew that there were weapons in the home but did not notify responding officers , three of whom were fatally shot , an official said Tuesday . Eric Kelly , from left , Paul Sciullo III and Stephen Mayhle were shot to death responding to a 911 call . The officers died Saturday in a gunbattle as they were responding to the call , authorities have said . `` It was pure human error and a terrible thing that occurred , '' Bob Full , chief of emergency services for Allegheny County , told CNN affiliate WTAE . `` In this particular case , our call-taker did not follow through with the appropriate training that she had received and -LSB- make -RSB- the appropriate notation that there were weapons in the house . '' The bodies of the Pittsburgh police officers -- Stephen Mayhle , Paul Sciullo III and Eric Kelly -- are scheduled to lie in repose at Pittsburgh 's city-county building Wednesday before a public memorial is held Thursday . Richard Poplawski , 22 , is in custody in connection with the shootings . He was hospitalized over the weekend after being shot in the leg during the gunbattle and standoff with police that lasted four hours . Police have not disclosed where he is being held . They said he would be charged with three counts of homicide , aggravated assault and other charges . Poplawski 's mother , Margaret , called 911 about 7 a.m. Saturday to report that her son was `` giving her a hard time , '' according to a criminal complaint filed in the case . She told police she awoke to discover that `` the dog had urinated on the floor '' and awakened her son `` to confront him about it , '' and the two argued . Margaret Poplawski told her son that she was calling police to remove him from the home , the complaint said . During that call , according to WTAE , the dispatcher asked Margaret Poplawski , `` does he have any weapons or anything ? '' referring to her son . The woman replied , `` Yes . '' She paused and then said , `` they 're all legal . '' `` OK , but he 's not threatening you with anything ? '' the dispatcher asked . WTAE reported that Margaret Poplawski did not answer directly but said , `` look , I 'm just waking up from a sleep , and I want him gone . '' Full pointed out that the call was a `` casual conversation '' and that although `` there 's no excuse for it whatsoever ... gathering from the casual nature of the call , the call-taker took an inference that -LSB- the caller -RSB- was not threatened and that guns or weapons were not involved . And it never was relayed to the police officers . '' Authorities said the responding officers , Mayhle and Sciullo , were shot as they arrived at the home . Kelly was shot later as he arrived to help them . Police believe that Poplawski , wearing a bulletproof vest , fired more than 100 rounds at officers with an AK-47 , another rifle and a pistol , authorities said Saturday . The dispatcher has been placed on paid administrative leave , Full said . `` You can only imagine how fragile this individual is . This young lady came to work that day ... she had no intentions on ever letting this go . '' The woman is being assisted through the county 's employee assistance program , he said . Pittsburgh Mayor Luke Ravenstahl said in a statement that , although he has commended the county 911 center many times , Saturday 's events `` revealed a flaw in the 911 system . '' `` We now know that the 911 dispatcher was made aware that guns were present ... and that this information was not communicated to the officers , '' Ravenstahl said , according to WTAE . `` Before responding to the call , the officers should have had the benefit of knowing that the actor owned firearms . We will never know if Saturday 's events would have gone differently had the officers known . '' Ravenstahl said he has asked the center 's management to develop a plan of action `` to address flaws in the system and to ensure that this type of incident never happens again , '' WTAE reported .