have served time in Illinois prisons.The Mattcson resident is WalterMancino, 32, who was captured.when he tried to slip through acordon of police which- suddenly surrounded his'home ai 5:30 a. m.rs.d-Tuesday;The Chicagoans, two brothers who are said to have been cell-• 3mates of Mancino, are Jerome and Wilbur Williarhs, 35 and- 33 yearsold. resoectivelvl A' fourth man.rs.n-Augie Vendetti, 18, of 44 WestTwenty-third street, said by policeto be a pal of Mancino, also is in police custody,- charged with a Kankakee robbery. . •Service Stations Raided9ncino and the Williams-brothers, police reported, are linked with some 15-robberies committed in Chicago. Chicago Heights, Harvey and Kankakee between November and February’ All of the robberies except one here weredirected against -service stations.The three are being held on open charges at the Shakespeare avenuepolice station, Chicago, to awaithearing — probably today — in Felony court. The state's attorney'soffice reported • that .the suspects already have admitted’ their guiltto most of the offenses.. .Many of the victims made-positive iden-er tification at a “show-Vp'.’- Tuesday-Id. night, it was reported.Despite the large number of rs. stick-ups, police said, it is bejieV-j ed the trio didn’t, net more than SI.000 in loot. Arrest .of the elderlitbe I Williams brother led to the round-a- I up of the gang, the state's attorney's office said. Jerome was pick-r_ cd up by Chicago police Saturday ,n as a su'spcct in the murcjer of Mrs. Esther Libert, mother of five cbil-ChicagoWest side several weeks ago.rs j Implicates OthersWhile in custody, police said, heimplicated his brother and Mart-cino, and that ‘'started the bail