Montgomery County Lawyer David Manilla has pleaded no contest to involuntary manslaughter in a Bucks County hunter’s death. He also pleaded guilty to related offenses including illegal firearms possession.  With a “no contest” plea he is not admitting guilt, but he is admitting that prosecutors have enough evidence to convict him.  At sentencing it is treated the same as a guilty plea.  Prosecutors say the 49-year-old Manilla, of Worcester, shot 52-year-old Barry Groh of Quakertown with a high-powered rifle as Groh was dragging a deer along the Tohickon Creek in Richland Township on opening day of the firearms deer season last November.  Defense lawyer Keith Williams said Manilla took responsibility for his actions and he was regretful, but Deputy Bucks County District Attorney Bob James said the guilty plea was half-hearted and Manilla did everything he could to avoid prosecution.  Williams said he will bring up mitigating circumstances at Manilla’s sentencing in July, including serious health problems and prior treatment for mental illness.  He also faces a wrongful death lawsuit filed by Groh’s family.